air. They are decomposed by water more or less rapidly,
and give the corresponding acid and hydrochloric acid, which
may be tested for. They are also acted on rapidly by strong
ammonia, and give the amide, the melting-point of which may
be ascertained (p. 209).
/Jti/w/i Acith and Esftrs.Most of the insoluble halogen
acids belong to the aromatic series, and have a distinctive
meltim;~point. For further confirmation, they maybe converted
into the acid chloride and amide. Insoluble esters containing"
halogens may belong to both series, and the acid and alcohol
must then be separated and separately investigated.
4. The following among the more common organic substances
contain sulphur or sulphur and nitrogen in addition to carbon,
hydrogen and oxygen.
nil; v , 1 1
, ; i ii 1 1 r>
( n v » li, v ;, n, iliui
Allyi iluocyanatu .
(p. 160) ....
1 7 ri
uinide (p. 179)
iiilf (p. i7<:>) . .
Mixturaa A preliminary investigation carried out as
ih-scribed on p. 322 will determine roughly if the substance is a
mixture. Before proceeding to identify the substances present,
it is essential that they should first be s^arated. This may be
a lonK and difficult operation, but the following methods may
lead to the desired result.
** If the :.ul.« taru'e cannot be satisfactorily separated by fractional